An electromagnetic valve for rebreathing exercise studies.

An electromagnetic valve for use in exercise rebreathing studies is described. This valve enables the investigator to connect a rebreathing system immediately after the onset of inspiration even at high breathing frequencies. The rapid switching causes minimal leakage; the rebreathing bag can be washed out and refilled without disconnection during exercise testing. For one year this valve has been used in measurements of functional residual capacity and diffusing capacity during exercise in volunteers as well as in patients.